Peter Reid has warned his Sunderland players they must keep their heads after receiving notice of the Wearsiders' fourth suspension of the campaign.

The Black Cats' boss was last night relieved to hear that Emerson Thome will not face a trial by television as a result of his clash with controversial Leeds striker Alan Smith at the Stadium of Light on November 18.

But that good news was quickly tempered by confirmation from the Football Association that Bernt Haas will miss the club's home clash with Chelsea on December 8.

This is because he picked up his fifth yellow card of the season at Anfield on Sunday. Reid has already had a rap on the knuckles from the FA as punishment for Sunderland finishing the last campaign at the bottom of the Premiership's Fair Play League.

As a result, the club have a #50,000 suspended fine hanging over them.

And disciplinary chiefs have warned Reid to crack down on last season's record of 77 yellow cards and six sendings off.

But already this term the Black Cats have accumulated 28 bookings in their 14 matches.

And that could prove costly to Sunderland - both in terms of cash and the loss of key players.

The Wearsiders kicked-off their campaign against Ipswich without the services of the suspended Don Hutchison while Thome served a three-match ban soon after as a result of his red card in a pre-season friendly in Holland over the summer.

Gavin McCann sat out the visit of Premiership champions Manchester United last month as a result of his five bookings this season - the same fate that now awaits Haas.

The Swiss international collected his fifth yellow card for a foul on Liverpool's Vladimir Smicer in the move that led to Emile Heskey's winning goal in the first half at Anfield on Sunday.

And Haas was later involved in the incident that saw Dietmar Hamann sent off for a two-footed tackle, an incident that Liverpool intend to mount an appeal against. Thome could have faced his second ban of the season had the FA decided to call on their Video Advisory Panel to probe his clash with Smith - sent off against Aston Villa at the weekend - in Sunderland's 2-0 defeat of Leeds.

But having received the report of match referee Graham Barber, the FA have confirmed that no action will be taken against the Brazilian.

Swedish midfielder Stefan Schwarz is currently just one booking away from a mandatory one-match ban, with four yellow cards to his name this term.